It all depends on your willingness to accept the challenges each unit presents.
A gas unit gets it done, but it's a rougher, noisier ride, wind does push it around. I managed 4 hours of driving comfortably, but it was work.
A diesel C is much like my school bus, holds the road in all conditions. It's not as noisy as a V10 thats down shifting for every hill with the rpms screaming. But it will produce front engine noise and heat, depending on how it's built it may have heat from the engine through the drive shaft to the rear wheels like most gas A's. Most have rear air ride so it's easier to drive 6 to 10 hrs comfortably.
A diesel pusher, our latest MH is quiet to drive, and has air ride all around. Ours is older an 07, No DEF, reasonably priced and reliable, unlike the newer diesels I drive for work. This golden oldie doesn't have the common dash lights on I deal with in the newer diesels. The Re gen, exhaust plugged, DEF issues, water in fuel, etc, dash lights and the nasty "you go nowhere while I regen" Had that happen at a red light, with a 40' school bus on a hwy with 45 kids and a 12' trailer. It's designed to go into regen mode when the particle filter is clogged and to over ride it you put it in Nuetral and press the brake, but it doesn't always clear it. I despise the newer diesels!!! Yet I "get to" drive them for work.
When we replaced the exhaust manifold on the 07 the mechanics said they loved this motorhome because ALL work was done from the outside while it was on the lift.
Yes a diesel is more expensive to maintain, but again its all about your comfort zone. We are comfortable with this old girl and it meets all our needs/wants and the price was right.
Good luck with the adventure of finding what will work for you. It's out there, just be patient.